RUKO FLS-DIN373-HSS-TiN-M12x Countersink Bit

Creating precise counterbores for M12 screw heads in tough materials like steel and cast iron demands a tool that stays sharp and accurate. The RUKO FLS-DIN373-HSS-TiN-M12x countersink bit is engineered for exactly that task, combining high-speed steel with a titanium nitride coating to deliver clean, burr-free results in metalworking and machining applications.

Who is it for

Machinists, metal fabricators, and maintenance professionals who need a reliable countersink for preparing holes for M12 screws in steel, cast iron, non-ferrous metals, and plastics. It suits both CNC and manual operations where precision and tool life are critical.

Main features

• Conforms to DIN 373 standard for countersinks
• High-speed steel (HSS) body with titanium nitride (TiN) coating
• Three-flute design for smooth cutting and efficient chip evacuation
• 90° cutting angle for standard countersunk screw heads
• Cylindrical shank with 10.0 mm diameter for secure tool holding
• Right-hand cut direction

Specifications

• Standard: DIN 373
• Material: High-Speed Steel (HSS)
• Coating: Titanium Nitride (TiN)
• Intended screw size: M12
• Pilot diameter (d1): 13.0 mm
• Countersink diameter (d2): 20.0 mm
• Shank diameter (d3): 10.0 mm
• Overall length (l1): 67 mm
• Pilot length (l2): 18 mm
• Number of flutes: 3
• Cutting angle: 90°
• Shank type: Cylindrical
• Tool type: Countersink / Counterbore
• Recommended materials: Steel, Cast Iron, Non-ferrous metals, Plastics
• Manufacturing process: Ground profile
• Surface hardness (TiN): Approx. 2300 HV
• Thermal stability (TiN): Up to 600°C
• Coolant use: Recommended for optimal performance in hard materials
• Direction of cut: Right-hand cut

Tips

Use cutting fluid when working with steel or cast iron to extend tool life and improve surface finish. Ensure the workpiece is securely clamped to prevent vibration and achieve accurate counterbores.